> I need some help building my setup
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dineontitan |
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Class : Apprenti
Posts : 6
Registered on : 07/08/2015
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Hi all,
I really want to build my own tracking system, and i've done some things already.
My camera is ready and working, i've bought some leds and have some batteries and resistors here.
The only problem here is that I don't know that much about which resistors to use and how to use them exactly.
The batteries I have are 2 1,2 rechargeable batteries. Edit: 1 battery has 2300 ma
I have 3 IR leds that have need 130 ma as forward current and 1.30 V as forward voltage with 100Ma(not sure about this as there are 2 things in the sheet).
I have tried looking into the forums here but I wasn't really able to figure it out, but I think I need to build a parallel build because of the 1,2 volt batteries.
Greetings Dineontitan
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Stormrider |
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Class : Légende du Forum
Posts : 466
Registered on : 02/01/2013
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hi,
as a powersource you have 2,4V(2 batteries of 1,2V)
Your leds have a forwarding voltage of 1,3V.This means that if you want to make a serial model your powersource must have at least a minimum 3x1,3=3,9V
As you can see your 2 batterries are not enough, therefor you can make a paralel model.Every led his own resistor.Because the leds are connected paralel to your powersource, the will all see that 2,4V.
for one led, serial connection
(powersource voltage- forwarding voltage led)/desired current=resistor value
(2,4v-1,3v)/0.07A=15,7 ohm
So every led must have a resistor of 15 ohm.
That value of 100mA is probably the maximum current, it is better to use less current.
regards Stormrider
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dineontitan |
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Class : Apprenti
Posts : 6
Registered on : 07/08/2015
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Thanks!
I will try this and see how far I will come.
It's a lot more clearer to me now, I really should've paid attention to it last year in school  |
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Stormrider |
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Class : Légende du Forum
Posts : 466
Registered on : 02/01/2013
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asking here goes faster 
that resistor value, maybe order a few of diffent value.You don't know yet how bright your leds will shine.Because of you using batterries, the higher the used resistor value the longer your batteries will last.This is something you have to find out by trying. |
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dineontitan |
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Class : Apprenti
Posts : 6
Registered on : 07/08/2015
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I probably am going to take a look at the local electrics store tomorrow, but it's known as very expensive.
I don't want to spend way too much money there either.
I might as well order them online for 10 cents
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dineontitan |
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Class : Apprenti
Posts : 6
Registered on : 07/08/2015
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Alright so i got the resistors and they are working properly.
Now I got to the next problem which is that the viewing angle on the leds is very small.
I know that you can file them down, so I did that, but now the problem is that the led is not visible anymore unless you have it really close to the camera.
Is there something I have done wrong?
The leds i currently have are the siemens ld271
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Stormrider |
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Class : Légende du Forum
Posts : 466
Registered on : 02/01/2013
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what you can try is enable auto exposure, remove your normal light filter,shine with a very bright light into the webcam and disable auto exposure, put your normal light filter back and try if you can see your leds.
By the way, what webcam are you using?
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dineontitan |
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Class : Apprenti
Posts : 6
Registered on : 07/08/2015
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I am using the logilink USB webcam, it looks a lot like the a4tech recommended on this site.
But I have already replaced the faulty led and it is working now
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Stormrider |
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Class : Légende du Forum
Posts : 466
Registered on : 02/01/2013
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